This invention relates to the field of integrated circuits. More particularly, this invention relates to integrated circuits using cobalt silicide (CoSi2) on silicon Schottky diodes.
Schottky diodes are used in electronic circuits to provide low voltage drops in forward biased operation and low leakage currents in reverse biased operation. The current art integrates cobalt silicide on silicon Schottky diodes into the BiCMOS fabrication process. Cobalt silicide Schottky diodes are fabricated by forming cobalt silicide in a region on the surface of a lightly doped n-type silicon layer. The current-voltage relationship of current art CoSi2 Schottky diodes is degraded by generation-recombination sites in the silicon under the Schottky junction. The current art Schottky diodes exhibit higher leakage current in reverse bias operation than comparable diodes with no generation-recombination sites. Leakage current in reverse bias operation is undesirable in most circuit applications.